Laravel Task Runner - how that might look like

runner.php

<?php

// in app/tasks.php

// the second argument contains the array of "dependencies"
task("default", ["minify_css", "minify_js", "concatenate"]);

// smart enough to analyze the arguments
// and "inject" required components
task("minify_css", function($minifyCss)
{
    // read as:
    // "scan the directory app/assets/css" and pipe all files through
    // $minifyCss component, then save it to public/css
    $this->in('app/assets/css')->pipe($minifyCss())->out('public/css');
});

task("minify_js", function($minifyJs)
{
    // you can even pass settings!
    $settings = [
        'keepComments' => true,
    ];

    $this->in('app/assets/js')->pipe($minifyJs($settings))->out('public/js');
});

task("concatenate", function($concatenator)
{
    $this->in('public/js')->pipe($concatenator())->out('public/main.js');

    $this->in('public/css')->pipe($concatenator())->out('public/main.css');
});